Sodium Dichromate is the chemical compound with the formula Na2Cr2O7. Usually, however, the salt is handled as its dihydrate Na2Cr2O7·2H2O. Virtually all chromium ore is processed via conversion to Sodium Dichromate. In this way, many millions of kilograms of Sodium Dichromate are produced annually. In terms of reactivity and appearance, Sodium Dichromate and potassium dichromate are very similar. The sodium salt is, however, around twenty times more soluble in water than the potassium salt (49 g/L at 0 °C) and its equivalent weight is also lower, which is often desirable.

Dichromate and chromate salts are oxidizing agents. For the tanning of leather, Sodium Dichromate is first reduced with sulfur dioxide.